Exactly. Freelancers need to be on assignment to get accreditation for many major events. The event doesn't care if u are staffer or freelancer. Just that you are working for a major media source. So the notion that a freelancer takes photos first then sells them after is not the way things work.

For example, many Getty pros are not on staff. They are independent contractors (freelancers). But unless they are on an actual assignment with an editor requesting credential, they aren't getting one.

It is not only the equipment used, but the infrastructure available.
Here is how Getty and AP manage their workflow, article also goes a bit into the kit each asset working for them goes into the field with.

A huge number of images daily are streamed directly from camera by WiFi or wire to server farms to editors and available within minutes of being taken for selection by publications.

Peter - great link. It really is interesting to hear how the whole process works now. How important Wifi has become and it also shows the fallacy in some people's thinking that "serious photographer don't use jpeg"

Interesting link. I had press credentials from a little Texas county paper and tried to get access to the F1 race in Austin.

They laughed at me and did not even offer me a discounted ticket.

I am always impressed with what the pro's are able to do. I have also learned that some of the great shot taking ability is practice with the sport in question so one knows where the lens should be pointed. (sometimes anyway)